1. Field of the Invention
This invention relates to a padlock having a replaceable cylinder. More specifically, the invention relates to a padlock having a cylinder assembly and which, when the lock is open, may be removed by the use only of an elongated element such as a wire, following which a second cylinder may be inserted and retained so that the keys used before the change will be ineffective to open the padlock after the change.
2. Description of the Prior Art
The prior art is replete with examples of padlocks wherein the cylinder may be removed and changed. Examples are:
Hanson U.S. Pat. No. 2,141,748, issued Dec. 27, 1938; PA1 Dequick U.S. Pat. No. 2,430,391, issued Nov. 4, 1947; PA1 Dies U.S. Pat. No. 3,187,525, issued June 8, 1965; and PA1 Lippisch U.S. Pat. No. 3,793,856, issued Feb. 26, 1974.
The prior art as a body, however, does not really teach a structure in which the cylinder may be removed and replaced with great ease and, at the same time, offer maximum security, unyieldably retaining the selected cylinder in the padlock body.